The aim of our study was to assess risk factors for hepatic artery thrombosis (HAT) and to evaluate the impact of HAT management on long-term outcomes after pediatric living donor liver transplantation (LDLT). We retrospectively analyzed 400 patients who underwent primary LDLT between 1999 and 2020. We compared preoperative data, surgical factors, complications, and patient and graft survivals in patients with HAT (HAT Group) and without HAT (non-HAT Group). A total of 27 patients (6.75%) developed HAT. Acute liver failure, a hepatic artery (HA) anastomosis diameter below 2 mm, and intraoperative HA flow dysfunction were significantly more common in the HAT Group (p < 0.05, p = 0.02026, and p = 0.0019, respectively). In the HAT Group, 21 patients (77.8%) underwent urgent surgical revision. The incidence of biliary stenosis and retransplantation was significantly higher in the HAT Group (p = 0.00002 and p < 0.0001, respectively). Patient and graft survivals were significantly worse in the HAT Group (p < 0.05). The close monitoring of HA flow with Doppler ultrasound during the critical period of 2 to 3 weeks after LDLT and the immediate attempt of surgical revascularization may attenuate the elevated risk of biliary stenosis, graft loss, and the need for retransplantation due to HAT.

Introduction: Preclinical models have demonstrated that PD-1 and its ligand programmed death ligand1 (PD-L1) play significant roles in both graft induction and the maintenance of immune tolerance. It has also been suggested that PD-L1 tissue expression may predict graft rejection; however, the available data are sparse and inconclusive. Some studies were conducted on patients with cancer; most of them do not concern the liver, especially within the context of the use of immunohistochemical tests. Therefore, the aim of our study was to assess the relationship between tissue expression of PD-L1 in a unique material, i.e., in the liver biopsies of pediatric patients after transplantation with the presence of acute cellular rejection (ACR). Material and Methods: This retrospective study enrolled 55 biopsies from 55 patients who underwent protocol liver biopsies. The control group consisted of 19 biopsies from 13 patients diagnosed with acute cellular rejection (rejection activity index/RAI/ from 2 to 8). An immunohistochemical (IHC) staining for PD-L1 was performed in all of the liver specimens; its expression was analyzed in different regions of liver tissue (in inflammatory infiltrates and within the endothelium and hepatocytes). The following changes were re-evaluated in each specimen: features of any kind of rejection (acute cellular, antibody-mediated, chronic); the presence and severity of fibrosis (Ishak scale); and the presence of cholestasis and steatosis. Clinical parameters were also evaluated, including tests of liver function (AST, ALT, GGT, bilirubin). Results: The age of patients in the study group ranged from 2.37 to 18.9 years (median 13.87 years), with the time after transplantation being 1–17 years (median 8.36 years). The age of patients in the control group ranged from 1.48 to 17.51 years (median 7.93 years), with their biopsies being taken 0.62–14.39 years (median 1.33 years) after transplantation. We found a statistically significant relationship between PD-L1 expression on inflammatory infiltrates and ACR; however, there was no statistically significant relationship between PD-L1 endothelial expression and ACR. PD-L1 was not positive in the hepatocytes regardless of if it was the study or control group that was under observation. Conclusion: PD-L1 appears to be a promising marker to predict graft rejection.

Introduction: Pectus excavatum (PE) is the most common chest wall deformity. Minimally invasive repair techniques based on the Nuss procedure are a mainstay of treatment. However, intraoperative cardiac injury, though rare, can be a devastating complication.Aim: This study aimed to evaluate a modification of the Nuss procedure designed to minimize the risk of serious complications.Material and methods: A retrospective analysis of medical records for 38 patients treated with a modified Nuss procedure forPE was conducted. The specific modifications to the surgical technique were described.Results: No intraoperative complications were observed in the analyzed patients. In 3 patients (7.9%), early complicationsafter surgery occurred, with none relating to the modification of the surgical technique.Discussion: Minimally invasive PE repair carries a risk of serious complications, prompting the development of variousmodifications. These modifications often involve techniques of sternal elevation and retrosternal dissection to achieve clearview throughout the procedure.Conclusions: The Nuss procedure with sternal elevation and thoracoscopic retrosternal dissection offers a simple andpotentially safer approach to PE repair.

Introduction Liver transplantation is currently an increasingly popular treatment method for patients with liver failure, both in adults and children. Antibody-mediated rejection (AMR), which is a very rare and poorly understood phenomenon, can lead to deterioration of graft function. The aim of the study was to analyze the clinical and histopathological manifestation of AMR in pediatric patients. Material and methods Sixty-two liver core biopsies from forty-two pediatric patients were included in this retrospective study. AMR was diagnosed in 7 children (in 10 biopsies), 35 demonstrated features of acute T-cell mediated rejection (TCMR) in 52 biopsies. C4d binding assay was performed in all biopsies using the immunohistochemical (IHC) method. The specimens were re-evaluated for signs of acute and chronic rejection, bilirubinostasis, and steatosis. Fibrosis was evaluated using a 6-grade Ishak scale. The Banff classification was used to assess TCMR activity. Evaluation of AMR was performed according to a newly developed original histopathological grading. Relationship between histopathological grading and morphological, as well as laboratory parameters was determined in each group depending on type of rejection. Statistical analysis was performed according to standard indications. Results The median age of patients (months) at the time of biopsy was 47.6 (15.03 – 98.83) and the median time from transplantation (months) was 0.9 (0.3 – 7.6). Results of the study brought evidence that histopathological lesions were the least specific manifestation suggesting AMR. Positive result of C4d staining with or without associated morphological abnormalities statistically increases the likelihood of AMR diagnosis. No statistically significant correlation was found between the type of rejection and laboratory tests. Conclusions: Diagnosis of AMR in transplanted liver is complicated and need to be complex. However, the proposed histopathological grading may be a helpful method for selecting patients who should be assessed for Donor-specific antibodies (DSAs) or in whom AMR should be suspected when DSA cannot be determined.